Dynamic Storage Tiering (DST) is a concept of grouping storage devices into tiers based on their performance characteristics and relocating data dynamically across the devices to leverage their specific capabilities. It is desirable that a DST system perform this relocation while data remains online and accessible.
For performance management, data that has a high activity or load level may be relocated it to high performing storage tiers. Alternately, data with a low activity level may be relocated to lower performing storage tiers in order to provide increased capacity in high-performance storage tiers.